Flow restricting device



May 16, 1950 F. Y. CARTER 2,508,224

FLOW RESTRICTING DEVICE Filed Aug. 9, 1946 FIGS 4 IN V EN TOR.

r A ATTORNEY W/(abw Patented May 16, 1950 FLOW RESTRICTING DEVICE Franklyn Young Carter, Dearborn, Mich., as-

signor to Detroit Lubricator Company, Detroit, Mich., a corporation of Michigan Application August 9, 1946, Serial No. 689,620

4 Claims.

This invention relates to a device for restricting the fiow of refrigerant to an evaporator.

An object of the invention is to provide a device of novel construction which can be readily manufactured at low cost.

.Another object is to provide such a device in which a filter of large capacity can be incorporated.

The invention consists in the novel construction and combination of parts to be more fully described hereinafter and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawings, to be taken as a part of this specification, there is fully and clearly illustrated a preferred embodiment of the invention, in which drawings:

. Figure 1 is an end view of the flow'restricting device;

Fig. 2 is an enlarged view in section on the line 2-2 of Fig. 1;

Fig. 3 is a view in section on the line 3-3 of Fig. 2;

. Fig. 4 is a view on the same scale as Fig. 1 and in longitudinal section on the line 44 of Fig. 2, and

Fig. 5 is a detail view of an end plate in section,

showing a modification.

Referring to the drawings by characters of reference, I designates a hollow internally cylindrical casing forming a cylindrical chamber 2. The casing has an end wall 3 from which a tubular inlet fitting 4 projects concentrically and is externally screw-threaded for connection to the refrigerant liquid line from the receiver or condenser.

The fitting bore or passageway 5 opens through the wall 3 into the chamber 2. Within the chamber 2 there is a hollow cylindrical flow member 6, there is an end plate 9 having its periphery serrated or notched to provide recesses 19 separated by teeth H. The radial depth of the notches or recesses H] is less than the thickness' of the member 6 but not less than that of the grooves 6. Each recess has a circumferential widthto span two of the grooves 8 so that each recess provides a return bend passageway between two adjacent grooves. The teeth ll 2 aline with alternate lands I and are of substantially equal width therewith. Through the plate 9 their is a central aperture I'z registering with the passageway 5. Radially through the member 6, there is a port or aperture !3 which opens into the inlet groove [4 of the grooves 8.

The other end of the casing I is closed by an end wall l5 in the form of a circular plate which is sealed to the casing. The plate l5 has a centrally positioned outlet fitting l5 which is externally screw-threaded to receive a conduit leading to an evaporator or refrigerating coil. The bore I! of the fitting I6 opens through the wall or plate 15. Clamped between and conforming to the opposed faces of the plate l5 and the adjacent end of the member 5 there is an end plate It! having its periphery serrated or notched to provide recesses I9 separated by teeth 20. The plate !8 is generally similar to the plate 9, except that one tooth 2| has a width to bridge thelands 1 at the sides of the groove l4 and thus block of! the lower end of the groove [4. The next adjacent groove 22 of the grooves 8, to the right of the inlet groove I4 facing Fig. 2, is in communication with the groove M at its upper end through a. return bend passageway ill. The teeth 20 are staggered or aline with alternate ones of the lands 1 relative to the alinement therewith of the teeth I I, so that the return bend passageways or recesses ill and !9 are a continuous zig-zag or sinuous flow restricting passageway having as its last pass or run, the groove 23 of the grooves 8, i. e. the groove next adjacent but on the left, facing Fig. 2, of the groove I4. The space or notch between the teeth 2! and the next adjacent tooth to the left thereof, provides an outflow recess which communicates with a radial groove or passageway 24 in the end wall 15. The inner end of the passageway 24 opens into the outlet fitting bore H. The member 6 and the end plates 9 and I8 are preferably made of extruded metal stock and may have the end faces of the lands and teeth ground toassure a leak proof fit with the internal surface of the casing l which may also be a ground surface. The end plates 9 and Hi can be made from the same stock piece and thereafter have the tooth 2| formed in part by an insert 25, see Fig. 5. The space or chamber 25 within the member e and between the plates 9 and It serves as a strainer or filter chamber. Clamped between the'plates I8 and the adjacent end of the member 5 there is a strainer supporting ring carrying a cup-like strainer 21 of fine wire mesh with its end wall adjacent the inlet passageway 5. The strainer cup is filled with filtering material 23 so that no foreign matter which might clog the grooves a can gain access thereto.

The operation of the flow restricting device, it having been connected in a refrigerant liquid line to an evaporator, is as follows: The liquid refrigerant enters the strainer chamber through the inlet passageway 5 and is filtered therein prior to discharge through the port 43'; The refrigerant then flows through the elongated sinuous passageway formed by the grooves 8 of small crosssectional flow area thereby limiting or restricting the flow to a predetermined amount-or ratein the same manner as the well known so-called capillary tube.

bore I! and thence to the evaporator.

Having thus described my invention, what is cylindrical member and one having an opening therethrough registering with said inlet, said end plates each having a tight sliding fit in said chamber and having peripheral-teeth and serrations of less radialdepth'than the wall thickness ofsaidcylindrical member, each of saidserrations having acircumferentialwidth to-register with two of=said grooves so that-eachserration" forms a. returnbendpassageway joining two adjacent grooves, said cylindrical member having a port which. opens from the interior thereof into one .of said. grooves, one of the teeth-of theother of said. end plates-havingawidthtto block off the end. of: said one groove" into which said port opens; thenextadjacent groove which is sepa rated: from said one groove" by a tooth of said one end plate being the outlet. groove, saidother endplate having'iteteeth alined with alternate ones of. the landswith whichthe teeth of said -one:plate aline;.therserration in-sa-id other platr which is alined with said outlet groove having communication with said outlet.

2. refrigerant flow restricting device, comprising-a casing havingacylindrical chamber and end closurewalls' for saidrc-hamber, one of: said wall; having an inlet therethrough, the other of. said: walls having an outlet therethrough, a

hollow cylindrical member? having a tight sliding fit in said chambenand having'straight longitu- =dinal alternate lands and grooves from end to 'enminits" externaiisurfa'cea' pair of end plates each abuttingone of said end walls and said cylindrical member: and one-having an opening '"theretliroughregistering with said-inlet, said end plates? each having a tight sliding fit in said chamber andfihaving peripheral teeth and serrations" of lessradial 'depth: than the wall thickness of said cylindrical member, each of said serrations having a circumferential width to register with two of: said grooves so that each serration forms a return bend-passageway joining; t'WGFadjaCEIItTgIOOVGS, said cylindrical member havingv a port which" opens from the interior thereof'into oneofsaidgrooves,one of the teeth ofthe other-of said endplates havinga width The restrictedflow discharges. through the radial groove 24 into the outlet fitting.

to block off the end of said one groove into which said port opens, the next adjacent groove which is separated from said one groove by a tooth of said One end plate being the outlet groove, said other end plate having its teeth alined with alternate ones of the lands with which the teeth of said one plate 'aline, one of the abutting surfaces between said cylindricalamember:and-said other plate having a radial groove leading to said outlet from the serration in said other plate which is alined with said outlet groove.

3. A refrigerant flow restricting device, comprising a casing having a cylindrical chamber and. end closure walls for said chamber, one of said walls having an inlet therethrough, the other of said walls having an outlet therethrough, a hollow-cylindrical member having a tight slidingfit-in said chamber and having straight longitudinal alternate lands and grooves from end to end in its external surface, a pair of end plates each abutting one of-said end walls and said cylindrical member and one having an opening therethrough registering with said inlet, said end plates each having a tight sliding fit in said chamber and having peripheral teeth and serrations of. less radial depth than the wall thickness of said cylindrical member, each of said serrations having a circumferential width to register with two of said grooves so that each serration forms a return bend passageway joining two ad'- ja'cent grooves, said cylindrical member having a port which opens from the interior thereof into one of said grooves, one of the teeth of the other of said end plates having a width to. block off the. end of said one groove into which said port opens, the next adjacent groove which is separated from said onegroove by a tooth of said one endpl'ate being'the outlet groove, said other end plate having its teeth alined with alternate ones of the lands with which the teeth of said one plate aline, one of the abutting surfaces between said cylindrical member and said other plate having a radial groove leading to said outlet from the serration in said other plate whichis alined with said outlet groove, and strainer means in said cylindrical .member.

4'. A refrigerant flow restricting device, comprising a casing having a ylindrical chamber andend closure walls for said chamber, one of said walls having an inlet therethrough, the other of said walls having an outlet therethrough, a hollow cylindrical member having a tight sliding fit in said chamber and having straight longitudinal alternate lands and grooves from end to end in its external surface, a pair of end plates. each abutting one of said end walls and saidcylindrical member and one having an opening therethrough registering with said inlet, said end .plates each having a tight sliding fit in said chamber and having penipheral teeth and serrations of. less radial depth than the wall thickness of. said cylindrical member, each of said serration's having a circumferential width to register withtwo of said. grooves so that each serration forms'a return bend passageway joining two adjacent grooves, said cylindrical member having a port which opens from the interior thereof into one of said grooves, one of. the teeth of the other of'said'en'd' plates having a width to block ofi the end of said one groove into. which said port opens, the next adjacent groove which is separated from said one groove by a tooth of said one end plate aline, one of the abutting surfaces between said cylindrical member and said other plate having a radial groove leading to said outlet from the serration in said other plate which is alined with said outlet groove and a cup-like strainer in said cylindrical member and having a supporting ring clamped between said other plate and said cylindrical member.

FRANKLYN Y. CARTER.

6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS- Number Name Date 2,069,630 Steenstrup Feb. 2, 1937 2,375,646 Grossi May 8, 1945 

